#!/bin/bash

# -------------------------------------------------------------------------- #
# Copyright 2002-2016, OpenNebula Project, OpenNebula Systems                #
#                                                                            #
# Licensed under the Apache License, Version 2.0 (the "License"); you may    #
# not use this file except in compliance with the License. You may obtain    #
# a copy of the License at                                                   #
#                                                                            #
# http://www.apache.org/licenses/LICENSE-2.0                                 #
#                                                                            #
# Unless required by applicable law or agreed to in writing, software        #
# distributed under the License is distributed on an "AS IS" BASIS,          #
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   #
# See the License for the specific language governing permissions and        #
# limitations under the License.                                             #
#--------------------------------------------------------------------------- #

###############################################################################
# This script is used to monitor the free and used space of a datastore
###############################################################################

# -------- Set up the environment to source common tools & conf ------------

if [ -z "${ONE_LOCATION}" ]; then
    LIB_LOCATION=/usr/lib/one
else
    LIB_LOCATION=$ONE_LOCATION/lib
fi

. $LIB_LOCATION/sh/scripts_common.sh

DRIVER_PATH=$(dirname $0)
source ${DRIVER_PATH}/../../datastore/libfs.sh

# -------- Get datastore arguments from OpenNebula core ------------

DRV_ACTION=$1
DS_ID=$2

XPATH="${DRIVER_PATH}/../../datastore/xpath.rb -b $DRV_ACTION"

unset i XPATH_ELEMENTS

while IFS= read -r -d '' element; do
    XPATH_ELEMENTS[i++]="$element"
done < <($XPATH     /DS_DRIVER_ACTION_DATA/DATASTORE_LOCATION \
                    /DS_DRIVER_ACTION_DATA/DATASTORE/TEMPLATE/BRIDGE_LIST)

unset i

BASE_PATH="${XPATH_ELEMENTS[i++]}/$2"
BRIDGE_LIST="${XPATH_ELEMENTS[i++]}"

# ------------ Compute datastore usage -------------

MONITOR_SCRIPT=$(cat <<EOF
if [ ! -d $BASE_PATH ]; then
    mkdir -p $BASE_PATH
fi

USED_MB=\$(df -B1M -P $BASE_PATH 2>/dev/null | tail -n 1 | awk '{print \$3}')
TOTAL_MB=\$(df -B1M -P $BASE_PATH 2>/dev/null | tail -n 1 | awk '{print \$2}')
FREE_MB=\$(df -B1M -P $BASE_PATH 2>/dev/null | tail -n 1 | awk '{print \$4}')

if [ -z "\$USED_MB" -o -z "\$TOTAL_MB" -o -z "\$FREE_MB" ]; then
    msg="Empty value found"
    echo "\$msg: USED_MB=\$USED_MB, TOTAL_MB=\$TOTAL_MB, FREE_MB=\$FREE_MB"
    exit 1
fi

echo "USED_MB=\$USED_MB"
echo "FREE_MB=\$FREE_MB"
echo "TOTAL_MB=\$TOTAL_MB"

vms=\$(ls "$BASE_PATH" | grep '^[0-9]\+$')

for vm in \$vms; do
    vmdir="${BASE_PATH}/\${vm}"
    disks=\$(ls "\$vmdir" | grep '^disk\.[0-9]\+$')

    [ -z \$disks ] && continue

    echo -n "VM=[ID=\$vm,POLL=\""

    for disk in \$disks; do
        disk_id="\$(echo "\$disk" | cut -d. -f2)"
        disk_size="\$(du -mL "\${vmdir}/\${disk}" | awk '{print \$1}')"
        snap_dir="\${vmdir}/\${disk}.snap"

        [ -z "\$disk_size" ] && continue
        echo -n "DISK_SIZE=[ID=\${disk_id},SIZE=\${disk_size}] "

        if [ -e "\$snap_dir" ]; then
            snaps="\$(ls "\$snap_dir" | grep '^[0-9]$')"

            for snap in \$snaps; do
                snap_size="\$(du -mL "\${snap_dir}/\${snap}" | awk '{print \$1}')"
                [ -z "\$snap_size" ] && continue
                echo -n "SNAPSHOT_SIZE=[ID=\${snap},DISK_ID=\${disk_id},SIZE=\${snap_size}] "
            done
        fi
    done

    echo "\"]"
done

EOF
)

if [ -n "$BRIDGE_LIST" ]; then
    HOST=`get_destination_host`
    MONITOR_DATA=$(ssh_monitor_and_log "$HOST" "$MONITOR_SCRIPT" "Remote monitor script" 2>&1)
else
    MONITOR_DATA=$(monitor_and_log "$MONITOR_SCRIPT" "Monitor script" 2>&1)
fi

MONITOR_STATUS=$?

if [ "$MONITOR_STATUS" = "0" ]; then
    echo "$MONITOR_DATA"
    exit 0
else
    echo "$MONITOR_DATA"
    exit $MONITOR_STATUS
fi
